Fix mouse handler binding for talking book tool (BL-16366)

[StephenMcConnel]

Also a bit of cleanup in that general area as well. I'm not sure these changes are needed in 6.5 since the bug was not manifesting there.

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This change is 

[greptile-apps]

Greptile Summary

This PR fixes the talking book tool's mouse handlers being silently dropped whenever the toolbox re-hydrates and replaces its DOM subtree. It also addresses related this-binding bugs in the WebSocket audio-level and mic-error listeners.

• All toolbar button handlers are migrated from direct jQuery bindings on individual elements to namespaced delegated handlers on $(document), so they survive the toolbox replacing its inner HTML. A wiredPlayer tracking field is added to detect when #player is replaced and re-attach its non-bubbling media events.
• audioLevelListener and micErrorListener are converted to arrow-function class fields and wrapped with a removeListener/addListener pair, fixing the this-is-undefined bug noted in prior review and preventing duplicate registration.
• WebSocketManager.removeListener gains an early-return guard so it is safe to call before any listener has been registered for a given context.

Important Files Changed

Filename	Overview
src/BloomBrowserUI/bookEdit/toolbox/talkingBook/audioRecording.ts	Rewires all toolbar button handlers to use jQuery delegated events on $(document) with namespaced events so they survive toolbox DOM re-hydration; converts audioLevelListener/micErrorListener to arrow-function class fields and adds remove-before-add idempotency; extracts wirePlayerHandlers() and tracks wiredPlayer to re-attach non-bubbling media events after re-hydration.
src/BloomBrowserUI/utils/WebSocketManager.ts	Adds an early-return guard in removeListener when clientContext has no registered callbacks, preventing a crash when removeListener is called before any addListener for that context.

_{Reviews (3): Last reviewed commit: "Fix mouse handler binding for talking bo..." | Re-trigger Greptile}